Internal-combustion engine



Dec. 9,' 1930. s. TISDALE 1,784,712

INTERNAL QOMBUST ION ENGINE File July 21, 1928 6Sheets-Sheet 1 QQ 80 753M,

INVENTOR ATTOR NEY Dec. 9, 1930. 1.. s. TISDALE 1,784,712

INTERNAL COMBUSTION ENGINE Filed y 21, 1928 3 Sheets-Sheet 2 INVENTORATTORNEY Dec. 9, 1930. 1.. s. TISDALE 1,784,712

INTERNAL COMBUSTION ENGINE Filed July 21, 1928 3 Sheets-Sheet 3 PatentedDec. 9, 1930' UNITED STATES LEO SINGLETOIV TISDALE, OF NEW ALBANY,MISSISSIPPI mrnmmn-connns'rron ENGINE Application filed Jui 21,

This invention relates to an internal combustion engine, the generalobject of the invention being to arrange the cylinders in pairs.- withthe combustion spaces of the cylinders of each pair connected togetherand with the power piston and its cylinder of smaller diameter than theother cylinder and piston of the pair, with the larger piston having agreater stroke than the smaller piston, with the parts so arranged thatthe smaller piston is beyond dead center when the charge is fired sothat the motor has the maximum power due to the increased area of thecombustion chambers and of the pistons and also due to the greatercompression of the charge andto the firing taking place with the powerpiston beyond dead center. This arrangement also eliminates back firingand makes the motor easier to start.

This invention also consists in certain other features of constructionand in the combination and arrangement of the several parts, to behereinafter fully described, illustrated in the accompanying drawingsand specifically pointed out in the appended claim.

In describing my invention in detail, reference will be had to theaccompanying drawings wherein like characters denote like orcorresponding parts throughout the several views, and in which Figure 1is a longitudinal sectional view through the improved motor.

Figure 2 is a section on line 2-2 of Figure 1.

Figure 3 is a section on line 3-3 of Figure 1.

Figure 4 is a transverse sectional view showing a modification.

As shown in these drawings, the cylinder block is formed with aplurality of cylinders arranged in pairs, the cylinder 1 of each pairbeingof less diameter than the cylinder 2 of each pair. The piston inthe small cylinder is shown at 3 and that in the .large cylinder isshown at 4.

The crank shaft is shown at 5 and the connecting rod 6 which connectseach piston 3 with the shaft is of less length than the rod 7 whichconnects the large piston of each pair was. Seri -1 no. 294,860:

withthe shaft. Thus the large piston has a longer stroke than the smallpiston and said piston 4, on its upwardstroke will pass to a pointpractically at the top of the large cylinder, while the small pistonstops a distance from the top of its cylinder so as to leave a Tcombustion chamber between itself and the top of the cylinder. An inletport 8 is'in communication with each of the cylinders 1 and this port iscontrolled by the inlet valve 9. An exhaust port 10 is in communicationwith each of the cylinders 2 and is controlled by the exhaust valve 11.A port 12 connects the upper ends of the cylinders 1 and 2 together.

The valves are controlled by the usual rocker arms 13 and push rods 14which are operated by the cams 15, the shaft 16 of which is geared tothe crank shaft by the gears 17. The cranks of the shaft 5 are soarranged that when each piston 4 is on dead center, each piston 3 willbe. beyond dead center, as shown in Figures 2 and 3, so that as soon asthe charge is fired by the spark plug 18, one of which is arranged ineach cylinder 1, the thrust of the connecting rod of the piston 3 on thecrank of the shaft will be instantly effective as the crank has movedbeyond dead center and after this action takes place, the crank of theshaft which is connected with the piston 4 will movesaid pistondownwardly past the port 12 so that some of the expandlng gases can acton this piston as well as the piston 3.

Thus I have produced an internal combustion motor of the maximum powerand in which the mixture is highly compressed before being exploded, asboth pistons act to compress the charge, with the small piston givingthe crank shaft its initial movement. The motor is also easy to startand there is no danger of back-firing.

Inthe modification shown in Figure 4, each pair of cylinders 1, and 2'is arranged in V formation and the upper ends of the two cylinders areconnected together by the pipe 19. In other respects, this form of theinvention is similar to that just described.

It is thought from the foregoing description that the advantages andnovel features of my invention will be readily apparent.

It is to be understood that I may make changes in the construction andin the com- 5 bination and arrangement of the several parts, providedthat such changes fall within the scope of the appended claim.

What I claim is An internal combustion engine comprising a plurality ofcylinders arranged in pairs,

withone cylinder of each pair of eater diameter than the other cylinder0 the pair, a piston in each cylinder, a crank shaft, connecting rodsconnecting the cranks 'of the shaft with the pistons, the connecting rodfor each large piston being of greater length that the connecting rodfor each small piston whereby each large piston will be moved upwardlyto a point close to the top of its cylinder, while each small pistonwill have its upward movement terminate a distance from the top of'itscylinder, the cranks being arranged with the cranks for the smallpistons beyond dead center when the cranks of the large pistons are ondead center, exhaust means connected with the top of each largecylinder, inlet means connected with the top of each small cylinder, anunobstructed passage connecting the top of each small cylinder with alarge cylinder a distance from the top of said la'r e cylinder, saidpassage being closed by t e large piston on the upward movement of thesame and the upward stroke of each small piston terminating short of thepassage and means in each small cylinder for ring the explosive mixturewhen the large piston is on dead center and the small piston is beyonddead center.

In testimon whereof I aifix my signature. 40 K LE SINGLETON TISDALE.

